Spinal cord stimulators are devices that are placed into the epidural space of the spinal canal and are designed to apply electrical stimulation to the dorsal column of the spinal cord (e.g., between T7-T12) to modify the pain responses from the back and legs to the brain. The epidural lead is connected to a battery/generator, usually implanted down in the patient's buttock area. In patients with chronic back and/or leg pain, these devices can provide significant pain relief and improvement in quality of life.
Currently the standard of care for using spinal cord stimulators to treat back and/or leg pain requires a percutaneous trial of the device for 4-7 days to see if the spinal cord stimulator gives adequate coverage and relief of the patient's pain. If the trial is successful, a permanent epidural lead is placed.
There are typically two options for permanent placement. With the first option, one or two leads may be placed percutaneously as in the trial using a large spinal needle to introduce the lead into the epidural space. The lead is then anchored down with a suture to the muscle fascia and then tunneled to the generator. While this is relatively less invasive and may be performed by the pain management physician without a surgeon, it may be disadvantageous in that with only 1 or 2 leads it is often difficult to find the same coverage as in the trial, possibly due to secondary scarring from the trial.
As for the second option, placement of a “paddle” lead is performed by surgically opening the spinal canal with a hemi-laminectomy and placing a wider lead with 2-5 rows of leads. A potential advantage of this approach is that with the extra leads each having several contacts, the likelihood of finding good coverage of the patient's pain is improved. However, this requires a spine surgeon to open the spinal canal and place the lead. This technique may also be utilized if the percutaneous permanent placement is not working as well as the trial.
As a result, it may be desirable to provide further improvements to spinal cord stimulator systems and associated methods for the implantation thereof which may provide higher success rates for percutaneous placement to help avoid more traumatic or invasive lead placement procedures.